Shrinkproofing textiles with polyepoxides and ammonia



United States Patent SHRINKPROOFING TEXTILES WITH POLY- EPOXIDES AND AMMONIA Thompson J. 'Coe, Albany, Calif., assignor to the United States of America as represented by the Secretary of Agriculture No Drawing. Application May 12, 1958 Serial No. 734,797

6 Claims. 01. 8-128) (Granted under Title as, US. 'Code 1952 see. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all advantages of the invention will be evident from the following description.

' It is well known in the art that many textile fibers exhibit poor dimensional stability. For example, launderin'g' causes severe shrinkage of woolen textiles. This technical disadvantage seriously restricts the applications of wool in the textile industry and much research has been undertaken in order to modify the natural fibers in order to improve its shrinkage properties. In general, known methods of treating wool to improve its shrinkage characteristics have the disadvantage that the hand of the fabric is impaired, or, if the amount of agent applied is limited to avoid impairment of hand, the degree of shrinkage protection is relatively poor.

' In accordance with the invention, wool, or other textile material, is impregnated with a polyepoxide then cured by subjection to ammonia in the vapor state. This procedure yields a product which is virtually shrinkproof under normal laundering procedures while the hand, resiliency, porosity, tensile strength, color, and other valuable properties of the textile are retained. Additionally, the treated textile exhibits a great improvement in resistance to creasing and wrinkling as compared to the original textile.

The prior art discloses methods for shrinkproofing textiles by applying polyepoxides and curing the polyepoxide with such agents as triethylamine, ethylene diamine, diethylene triamine and other amino compounds. The curing method of the invention-involving subjection to ammonia in the vapor phase-oflers many advantages over the known curing techniques, as follows:

(a) In curing with ammonia the original color of the textile is retained. For example white wool remains white after the curing with ammonia. On the other hand curing with polyamines causes the treated wool to turn yellow- Dyed textiles treated in accordance with the invention retain their original color in undiminished brightness whereas curing with amines causes a graying or dulling of the fabric.

' (b) Curing with ammonia in the vapor phase has the advantage that this curing agent can penetrate readily with the textile and ensure complete and uniform cure of the polyepoxide.

(c) The vapor phase ammonia treatment does not disturb the appearance, dimensions, or construction of the textile. There is no change in nap, no wrinkling. Textileshaving pleats, folds, etc., retain such forms without change.

(d) Since the curing involves a vapor phase rather than the usual liquid treatment, no wringing or other mechanical treatments are required. This means that no wrinkling or other change in the construction or arrangement of the textile is involved.

(e) The curing with vaporous ammonia yields products of especially soft and resilient and more shrinkproofing 'elfect per unit weight of resinous material deposited on the fibers is obtained.

In applying the process of the invention in practice, the textile is first impregnated with a liquid preparation of the polyepoxide. The impregnation is performed in any of the usual ways. For example, the polyepoxide composition is applied by spraying, brushing, dipping, etc. To assist in wetting the textile, it may be run through padding rolls or the like. Excess liquid may be removed by passing the textile through wringer rolls. The proportion of active material in the liquid preparation is usually so selected that there is deposited on the textile about /2 to 10% of its weight of polyepoxide. In general, the greater the proportion of polyepoxide, the greater will be the shrinkage protection afiorded. After the textile has been treated with the polyepoxide preparation it may be cured directly or dried in air prior to curing, the latter procedure being generally preferred.

Curing of the polyepoxide-impregnated textile involves subjecting it to the vapors of ammonia. This may conveniently be done by hanging the textile in a chamber in which is exposed an open vessel containing ammonium hydroxide. In the alternative, ammonia gas from a tank may be bled into the chamber. No special precautions need be taken as to addition or elimination of moisture from the system. The textile is allowed to remain in contact with the ammonia vapors until the polyepoxide is cured, that is, until it is rendered insoluble so that it is not removable from the textile by laundering. The temperature of the ammonia vapor may be at room temperature or may be increased to about 150 C. to obtain faster cure. At room temperature the cure is complete inabont 12 to 24' hours; at C. it is complete in about a half hour. No effort is made to control the amount of ammonia other than to ensure that the chamber at all times contains free ammonia so that an excess of ammonia is always available for reaction with the polyepoxide.

The polyepoxides used in accordance with the invention are organic compounds having at least two epoxy groups per molecule and may be saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or heterocyclic and may be substituted with non-interfering substituents such as' hydroxyl groups, ether radicals, and the like. epoxides containing ether groups, generally designated epoxide per mole of polyol. Thus, for example, epichlorhydrin may be reacted with a polyhydric phenol in an alkaline medium. In another technique the halogen-' containing epoxide is reacted with a polyhydric alcohol.

i'nthe presence of an acid-acting catalyst such as hydro? fluoric acid or boron trifluoride and the product is thenv reacted with an alkaline compound to elfect a dehydro-c halogenation, A preferred example of the halogencontaining epoxide is epichlorhydrin; others are epibromhydrin, epiodohydrin, 3 chloro' 1,2 epoxybutane, 3- and 3-chloro-1,2-epoxyoctane;

brorno-l ,2-epoxyhexane, Examples of polyols which may be reacted with the halogen-containing epoxide are glycerol, diglycerol, pro-- pylene glycol, ethylene glycol, diethylene glycol, butylene glycol, hexane triol sorbitol, mannitol, pentanetriol, pen-.1

3 taerythritol, dipentaerythritol, polyglycerol, dulcitol, inositol, carbohydrates, methyltrimethylol propane, 2,6- octanediol, tetrahydroxycyclohexane, 2-ethyl hexanetriol- 1,2,6, glycerol methyl .ether, glycerol allyl ether, polyvinyl alcohol, polyallyl alcohol, resorcinol, catechol, hydroquinone, 4,4-dihydroxydiphenyl ether, methyl resorcinol, 2,2-bis (parahydroxyphenyl) propane, 2,2-bis (parahydroxyphenyl) butane, 4,4-dihydroxybenzophenone, bis (parahydroxyphenyl) ethane, 1,5-dihydroxynaphthalene, l,4-dihydroxycyclohexane, his (2,2-dihydroxydinaphthyl) methane, etc. Illustrative examples of polyepoxide polyethers are as follows:

1,4-bis (2,3-epoxypropoxy) benzene; 1,3-bis (2,3- epoxypropoxy) benzene; 4,4-bis (2,3-epoxypropoxy) diphenyl ether; 1,8-bis (2,3-epoxypropoxy) octane; 1,4- bis (2,3-epoxypropoxy) cyclohexane; 4,4'-bis (2-hydroxy- 3,4-epoxybutoxy) diphenyl dimethylmethane; 1,3-bis (4,5-epoxypentoxy)-5-chlorobenzene; 1,4-bis (3,4-epoxybutoxy) -2-chlorocyclohexane; diglycidyl 'thioether; diglycidyl ether; ethylene glycol diglycidyl ether; propylene glycol diglycidyl ether; diethylene glycol diglycidyl ether; resorcinol diglycidyl ether; 1,2,3,4-tetrakis (2-hydroxy- 3,4-epoxybutoxy) butane; 2,2-bis (2,3-epoxypropoxy- 'phenyl) propane; glycerol triglycidyl ether; mannitol tetraglycidyl ether; pentaerythritol tetraglycidyl ether; sorbitol 'tetraglycidyl ether; etc. It is evident that the polyepoxide polyethers may or may not contain hydroxy groups, depending primarily on the proportions of halogen-containing epoxide and polyol employed. Polyepoxide polyethers containing polyhydroxyl groups may also beprepared by reacting, in known manner, a polyhydric alcohol or polyhydric phenol with a polyepoxide in an alkaline medium. Illustrative examples are the reaction product of glycerol and diglycidyl ether, the reaction product of sorbitol and bis (2,3-ep0xy-2-methylpropyl) ether, the reaction product of pentaerythritol and 1,2,4,5-diepoxy pentane, the reaction product of 2,2-bis (parahydroxyphenyl) propane and his (2,3-epoxy-2 methylpropyl) ether, the reaction product of resorcinol and diglycidyl ether, the reaction product of catechol and diglycidyl ether, and the reaction product of 1,4-dihydroxycyclo-hexane and diglycidyl ether. A particularly preferred type of polyepoxide polyether is that prepared by reacting epichlorhydrin with 2,2-bis (parahydroxyphenyl) propane. The structure of these compounds is illustrated by the formula:

ventional emulsification agent. For this purpose one may employ agents such as soaps, long-chain alkyl sulphates, long-chain alkyl benzene sulphonates, alkyl esters of sulphosuccinic acid, etc., typical examples being sodium lauryl sulphate, sodium alkyl (C -C benzene sulphonate, sodium dioctylsulphosuccinate, etc. Preferably, emulsifying agents of the non-ionic type are employed, for example sorbitan laurate, polyoxyethylene ether of sorbitan monostearate, polyoxyethylene ether of sorbitan distearate, sorbitan trioleate, iso-octyl phenyl etherof polyethylene glycol, and so forth. Other suspending agents as gums, gelatin, pectin, soluble starch, dextrins, etc., can be used to keep the polyepoxide in suspension. It is obvious that the proportion of polyepoxide in the solution or dispersion may be varied as necessary to deposit on the textile material. the desired percentage of polyepoxide. i

The process of the invention is particularly adapted to the treatment of Wool, but is also advantageously applicable touother textiles including mohairs; animal hair; silk; fibers made from proteins such as zinc, casein, peanut protein, soybean protein, keratins, etc.; cotton; regen: erated cellulose; viscose; linen; cellulose acetate, etc. The textile material may be in the form of fibers, threads, yarns, woven or knitted fabrics, garments, etc. The invention is further demonstrated by the follow ing illustrative examples. i

Example I An aqueous emulsion was prepared containing 5% of polyepoxide and 2% of iso-octylphenyl ether of poly ethylene glycol (Triton X100), the latter'being lan emulsifying agent. The polyepoxide was a commercial product consisting essentially of 2,2-bis (2,3-epoxypropoxyphenyl) propane prepared by reacting epichlorhydrin with 2,2-bis (parahydroxyphenyl) propane. The above emulsion was padded onto pieces of white woolen cloth. The cloth was dried in air. The pickup of polyepoxide was 2.5%, based on the weight of cloth. The polyepoxide-impregated cloth was then placed in a chamber containing ammonia gas at 125 C. One set of samples was held in the chamber /2 hour, another set 1 hour. The cloth samples were then removed from the ammonia chamber. It was observed that both samples were white in color.

The treated samples of cloth and a sample of untreated CH: O

wherein It varies between zero and about 10, corresponding to a molecular weight about from 350 to 8,000.

Polyepoxides which do not contain ether groups may preferred to apply the polyepoxides in the form of aque-' ous emulsions prepared by application of any of the known emulsification techniques. A preferred procedure is to dissolve the polyepoxide in a suitable quantity of alcohol or other volatile organic solvent and add this solution to water with vigorous agitation. In this way contact of the solution with water will precipitate the polyepoxide in minute particles which will be relatively easy to emulsify. To assist in forming and maintaining the emulsion, one may add a small proportion of a Q011- cloth (control) were subjected to tests to determine their shrinkage characteristics. In these tests the cloth samples were subjected to a laundering operation wherein the cloth was violently agitated in an Accelerotor for 3 minutes at 0.5% solution of sodium oleate at 40 C. with a cloth to solution ratio of 1 to 35. The area of the cloth was measured before and after laundering. The washing tests; were carried out in duplicate. The results are tabulated below, the shrinkage values being averages of the duplicate tests- Area Time of shrinkage Sample NHa cure,

hrs. daring,

percent OHX p Example 11 Pieces of White woolen cloth were padded with emulsions of polyepoxide having varying contents of this material assetforth below. In each case 2% of iso-octylphenyl ether of polyethylene glycol (Triton X") after laun- Pickup of Area Polyepoxcured shrinkage Sample ide in polyepox after launemulsion, ide by dering, percent cloth, percent percent Example 111 Samples of white woolen cloth were padded with emulsions of polyepoxide having varying contents of this material as set forth below. The same emulsifier as in Example I was used. The polyepoxide was the same as in Example I.

The emulsions were applied so that the cloth samples picked up about 100% of the weight of emulsion.

One-half the polyepoxide-impregnated samples were dried in air at 65 C. then cured. The other half were cured directly. The cure involving placing the cloth samples in a chamber containing ammonia gas. Temperature was 25 C. and the time of cure was 72 hours. It was observed that all the cured cloths were white. Shrinkage tests were carried out as described in Example I. The results are tabulated below.

6 Example IV A sample of woolen cloth was impregnated with a 10% emulsion of butadiene dioxide then placed in a chamber Where it was exposed to ammonia vapors for 72 hours at 25 C. The pickup of cured resin on the wool was 8.25%. The treated cloth was subjected to the washing test described above and it was found that it did not shrink but expanded about 1% in area.

Having thus described the invention, what is claimed is:

1. The method of shrinkproofing a textile without significant impairment of its hand which comprises impregnating the textile with about from 0.5% to 10% of its weight of a polyepoxide containing at least two epoxy groups per molecule and exposing the impregnated textile to ammonia in the vapor phase to cure and insolubilize the polyepoxide on the textile fibers.

2. The method of shrinkproofing wool without significant impairment of its hand which comprises impregnating wool with about from 0.5% to 10% of its weight of a polyepoxide containing at least two epoxy groups per molecule and being free from functional groups other than hydroxyl groups and exposing the polyepoxide-impregnated wool to ammonia in the vapor phase to cure and insolubilize the polyepoxide on the wool fibers.

3. The process of claim 2 wherein the polyepoxide is a polyglycidyl ether of 2,2-bis (parahydroxyphenyl) propane.

4. A shrinkproof textile of substantially unimpaired hand comprising textile fibers carrying an ammonia-vaporcured deposit of a polyepoxide containing at least two epoxy groups per molecule, in an amount about from 0.5% to 10% of the weight of the textile.

5. Shrinkproof wool of substantially unimpaired hand comprising wool carrying an ammonia-vapor-cured deposit of a polyepoxide containing at least two epoxy groups per molecule and being free from functional groups other than hydroxyl groups and epoxy groups, in an amount about from 0.5% to 10% of the weight of the wool.

6 The product of claim 5 wherein the polyepoxide is a polyglycidyl ether of 2,2-bis (parahydroxyphenyl) propane.

References Cited in the file of this patent UNITED STATES PATENTS 2,345,110 Graenacher et al. Mar. 28, 1944 2,730,427 Suen Jan. 10, 1956 2.8l7.602 Pardo Dec. 24, 1957 2,829,071 Schroeder Apr. 1, 1958 

1.
 2. ATHE METHOD OF SHRINKPROOFING WOOL WITHOUT SIGNIFICANT IMPARTMENT OF ITS HAND WHICH COMPRISES IMPREGNATING WOOL WITH ABOUT FROM 0.5% TO 10% OF ITS WEIGHT OF A POLYEPOXIDE CONTAINING AT LEAST TWO EPOXY GROUPS PER MOLECULE AND BEING FREE FROM FUNCTIONAL GROUPS OTHER THAN HYDROXYL GROUPS AND EXPOSING THE POLYEPOXIDE-IMPREGNATED WOOL TO AMMONIA IN THE VAPOAR PHASE TO CURE AND INSOLUBILIZE THE POLYEPOXIDE ON THE WOOL FIBERS. 